This invention is concerned with optical methods for manipulating one and two dimensional matrices.
Many signal and image processing algorithms can be expressed in terms of matrix operations. The mathematical functions of convolution and correlation, for example, may be implemented with matrix multiplication, which is one of the most basic operations in matrix algebra. An optical processing approach, with its inherent parallel processing capability, can offer significant improvements in the speed and capacity of such matrix operations. Such optical processors capable of multiplying two matrices are known in the art and optical matrix-vector multiplications have also been performed.
A typical optical processing system operates by directing one or more beams of light through an optical material of variable transmittance. The intensity of one of the light beams is modulated by a first input value, while the transmittance of the material is varied in accordance with a second input value. The solution of an equation containing the first and second input values is obtained by measuring the intensity of the beam after it passes through the optical material. Such an optical computing system can efficiently perform matrix operations when a mask for the input beam is subdivided into a plurality of separate zones and the zones are arranged in rows and columns to form a two dimensional matrix. The optical multipliers known in the art, however, utilize light modulators or transparencies to perform the multiplication and are consequently limited in speed, accuracy, and information capacity.